"A cheetah crouches in the tall grass. Pronghorn graze warily in the cool summer breeze. After minutes of quiet patience, the cheetah erupts into a burst of muscle and speed. You may be wondering, "What was a cheetah, a big African cat, doing chasing pronghorn, an iconic North American species?" You may be surprised to learn that North America used to be home to many animals you would recognize only on the African savanna, and many that you wouldn't recognize at all. This very scene may have played out in your own back yard, twenty thousand years ago."